A combined iron and thyroid hormone protocol suppresses ischemia–reperfusion injury in rat livers

Liver preconditioning (PC) against ischemia–reperfusion (IR) injury is attained by iron (Fe) or thyroid hormone (T₃) administration.

Combining animal personalities with transcriptomics resolves individual variation within a wild-type zebrafish population and identifies underpinning molecular differences in brain function

Resolving phenotype variation within a population in response to environmental perturbation is central to understanding biological adaptation. Relating meaningful adaptive changes at the level of the transcriptome requires the identification of processes that have a functional significance for the individual. This remains a major objective towards understanding the complex interactions between environmental demand and an individual's capacity to respond to such demands. The interpretation of such interactions and the significance of biological variation between individuals from the same or different populations remain a difficult and under-addressed question. Here, we provide evidence that variation in gene expression between individuals in a zebrafish population can be partially resolved by a priori screening for animal personality and accounts for >9% of observed variation in the brain transcriptome. Proactive and reactive individuals within a wild-type population exhibit consistent behavioural responses over time and context that relates to underlying differences in regulated gene networks and predicted protein-protein interactions. These differences can be mapped to distinct regions of the brain and provide a foundation towards understanding the coordination of underpinning adaptive molecular events within populations.

Thyroid hormone activates rat liver adenosine 5,-monophosphate-activated protein kinase: relation to CaMKKb, TAK1 and LKB1 expression and energy status

AMP-activated protein kinase (AMPK) is a sensor of energy status supporting cellular energy homeostasis that may represent the metabolic basis for 3,3,,5-triiodo-L-thyronine (T3) liver preconditioning. Functionally transient hyperthyroid state induced by T3 (single dose of 0.1 mg/kg) in fed rats led to upregulation of mRNA expression (RT-PCR) and protein phosphorylation (Western blot) of hepatic AMPK at 8 to 36 h after treatment. AMPK Thr 172 phosphorylation induced by T3 is associated with enhanced mRNA expression of the upstream kinases Ca2+ -calmodulin-dependent protein kinase kinase-beta (CaMKKbeta) and transforming growth-factor-beta-activated kinase-1 (TAK1), with increased protein levels of CaMKKbeta and higher TAK1 phosphorylation, without changes in those of the liver kinase B1 (LKB1) signaling pathway. Liver contents of AMP and ADP were augmented by 291 percent and 44 percent by T3 compared to control values (p less than 0.05), respectively, whereas those of ATP decreased by 64% (p less than 0.05), with no significant changes in the total content of adenine nucleotides (AMP + ADP + ATP) at 24 h after T3 administration. Consequently, hepatic ATP/ADP content ratios exhibited 64 percent diminution (p less than 0.05) and those of AMP/ATP increased by 425 percent (p less than 0.05) in T3-treated rats over controls. It is concluded that in vivoT3 administration triggers liver AMPK upregulation in association with significant enhancements in AMPK mRNA expression, AMPK phosphorylation coupled to CaMKKbeta and TAK1 activation, and in AMP/ATP ratios, which may promote enhanced AMPK activity to support T3-induced energy consuming processes such as those of liver preconditioning.

Pharmacokinetics and Pharmacodynamics of Warfarin When Coadministered With Pentosan Polysulfate Sodium

The effect of pentosan polysulfate sodium on warfarin pharmacokinetics and pharmacodynamics was investigated in healthy subjects. Warfarin was titrated to an international normalized ratio between 1.4 and 1.8. Subjects continued their titrated dose of warfarin and received pentosan polysulfate sodium 100 mg or placebo every 8 hours for 7 days. The Cmax of R- and S-warfarin was approximately 840 to 890 ng/mL and 680 to 730 ng/mL, respectively, and was similar in the absence and presence of pentosan polysulfate sodium. The half-life for R- and S-warfarin was 52 to 56 hours and 36 to 40 hours, respectively. Prothrombin time, partial thromboplastin time, and the international normalized ratio for warfarin + placebo and warfarin + pentosan polysulfate sodium were comparable. The AUC(INR) indicated no treatment effect (P = .772); however, there was a period effect. Analysis of variance for the treatments by period indicated no treatment effect (P > .1). Adverse events were mild and included headache, epistaxis, and rash. Most adverse events were unrelated to treatment and were seen during warfarin titration. Pentosan polysulfate sodium did not affect warfarin pharmacokinetics or pharmacodynamics.

Pharmacokinetics and Safety of the Ketolide Telithromycin in Patients with Renal Impairment

The pharmacokinetics and safety of the ketolide telithromycin were evaluated in two separate studies after single and repeat oral dosing in patients with varying degrees of renal impairment and in subjects with normal renal function. The single-dose study was an open-label, nonrandomized, parallel-group design in which all 40 patients received a single oral dose of telithromycin 800 mg. The repeat-dose study was an open-label study with a randomized, balanced, incomplete three-block treatment crossover design. In this study, each of the 36 patients received two of three telithromycin regimens (400, 600, or 800 mg once daily for 5 days), with a washout period of >/= 7 days between treatments. Telithromycin was well tolerated. Adverse events were generally mild in severity, and no serious drug-related adverse events were reported. Plasma exposure to telithromycin (C(max), AUC) showed a tendency to increase with increasing severity of renal impairment in both studies. In patients with severe renal impairment (CL(CR) < 30 mL/min) receiving telithromycin 800 mg in the repeat-dose study, C(max,ss) and AUC((0-24 h)ss) increased 1.5-fold (p < 0.05) to 2.0-fold (p = 0.0005), respectively, compared with healthy subjects. The percentage of dose excreted in urine and renal clearance (CL(R)) of telithromycin was found to decrease significantly with increasing severity of renal impairment in both studies, and CL(R) was found to be independent of telithromycin dose in the repeat-dose study. In conclusion, telithromycin dosage adjustment is not necessary in patients with mild to moderate renal impairment (CL(CR) >/= 30 mL/min). In patients with severe renal impairment (CL(CR) < 30 mL/min), dosage adjustment could be considered.

The 1918-1920 influenza pandemic in Peru

BACKGROUND

Increasing our knowledge of past influenza pandemic patterns in different regions of the world is crucial to guide preparedness plans against future influenza pandemics. Here, we undertook extensive archival collection efforts from three representative cities of Peru-Lima in the central coast, Iquitos in the northeastern Amazon region, Ica in the southern coast-to characterize the temporal, age and geographic patterns of the 1918-1920 influenza pandemic in this country.

MATERIALS AND METHODS

We analyzed historical documents describing the 1918-1920 influenza pandemic in Peru and retrieved individual mortality records from local provincial archives for quantitative analysis. We applied seasonal excess mortality models to daily and monthly respiratory mortality rates for 1917-1920 and quantified transmissibility estimates based on the daily growth rate in respiratory deaths.

RESULTS

A total of 52,739 individual mortality records were inspected from local provincial archives. We found evidence for an initial mild pandemic wave during July-September 1918 in Lima, identified a synchronized severe pandemic wave of respiratory mortality in all three locations during November 1918-February 1919, and a severe pandemic wave during January 1920-March 1920 in Lima and July-October 1920 in Ica. There was no recrudescent pandemic wave in 1920 in Iquitos. Remarkably, Lima experienced the brunt of the 1918-1920 excess mortality impact during the 1920 recrudescent wave, with all age groups experiencing an increase in all cause excess mortality from 1918-1919 to 1920. Middle age groups experienced the highest excess mortality impact, relative to baseline levels, in the 1918-1919 and 1920 pandemic waves. Cumulative excess mortality rates for the 1918-1920 pandemic period were higher in Iquitos (2.9%) than Lima (1.6%). The mean reproduction number for Lima was estimated in the range 1.3-1.5.

CONCLUSIONS

We identified synchronized pandemic waves of intense excess respiratory mortality during November 1918-February 1919 in Lima, Iquitos, Ica, followed by asynchronous recrudescent waves in 1920. Cumulative data from quantitative studies of the 1918 influenza pandemic in Latin American settings have confirmed the high mortality impact associated with this pandemic. Further historical studies in lesser studied regions of Latin America, Africa, and Asia are warranted for a full understanding of the global impact of the 1918 pandemic virus.

Spontaneous neural activity of the anterodorsal lobe and entopeduncular nucleus in adult zebrafish: a putative homologue of hippocampal sharp waves

Spontaneous neural activity is instrumental in the formation and maintenance of neural circuits that govern behavior. In mammals, spontaneous activity is observed in the spinal cord, brainstem, diencephalon, and neocortex, and has been most extensively studied in the hippocampus. Using whole-brain in vitro recordings we establish the presence of spontaneous activity in two regions of the zebrafish telenchephalon: the entopeduncular nucleus (EN) and the anterodorsal lobe (ADL). The ADL is part of the lateral telencephalic pallium, an area hypothesized to be functionally equivalent to the mammalian hippocampus. In contrast, the EN has been hypothesized to be equivalent to the mammalian basal ganglia. The observed spontaneous activity is GABA modulated, sensitive to glutamate and chloride transporter antagonists, and is abolished by sodium pump blockers; moreover, the spontaneous activity in the ADL is a slow multiband event (∼100 ms) characterized by an embedded fast ripple wave (∼150-180 Hz). Thus, the spontaneous activity in the ADL shares physiological features of hippocampal sharp waves in rodents. We suggest that this spontaneous activity is important for the formation and maintenance of neural circuits in zebrafish and argue that applying techniques unique to the fish may open novel routes to understand the function of spontaneous activity in mammals.

The zebrafish brain in research and teaching: a simple in vivo and in vitro model for the study of spontaneous neural activity

Recently, the zebrafish (Danio rerio) has been established as a key animal model in neuroscience. Behavioral, genetic, and immunohistochemical techniques have been used to describe the connectivity of diverse neural circuits. However, few studies have used zebrafish to understand the function of cerebral structures or to study neural circuits. Information about the techniques used to obtain a workable preparation is not readily available. Here, we describe a complete protocol for obtaining in vitro and in vivo zebrafish brain preparations. In addition, we performed extracellular recordings in the whole brain, brain slices, and immobilized nonanesthetized larval zebrafish to evaluate the viability of the tissue. Each type of preparation can be used to detect spontaneous activity, to determine patterns of activity in specific brain areas with unknown functions, or to assess the functional roles of different neuronal groups during brain development in zebrafish. The technique described offers a guide that will provide innovative and broad opportunities to beginner students and researchers who are interested in the functional analysis of neuronal activity, plasticity, and neural development in the zebrafish brain.

Total knee replacement in post-traumatic arthritic knees with limitation of flexion

The objective of this study is to investigate the results of total knee arthroplasty (TKA) in traumatic osteoarthritis cases with flexion restriction and to describe the technical details of their management. A multicentre series comprising 40 patients with limitation of flexion less than or equal to 90° was selected from 152 cases of post-traumatic knee arthritis with malunion. We hypothesized that the arthroplasty complication rate would be higher than in other etiologies of limitation of flexion and would require specific management strategies.

PATIENTS

In 23 cases, intra-articular malunion was present, in 15 cases extra-articular, and in two cases combined. The mean flexion was 72±23°, extension was 6±6°, and total range of motion (ROM) 66±23°. Eight cases of flexion restriction were severe (flexion<50°), six intermediate (flexion, 50-70°) and 26 moderate. In 14 cases, the anterior tibial tuberosity was osteotomized (43% intra-articular malunion and 6% extra-articular malunion). Five simultaneous realignment osteotomies were necessary. In severe cases of limitation of flexion, five extensive quadriceps releases were associated.

RESULTS

Four mobilizations under general anesthesia were performed. In the cases of severe limitation of flexion, we noted three avulsions of the patellar tendon, two cases of cutaneous necrosis, one of which was associated with deep infection, and another case of deep infection. In the cases of moderate limitation of flexion, we noted one case of nonunion of the tibial tuberosity and two cases were revised for loosening, one aseptic and the other septic. With a mean follow-up of 5±4 years, the mean flexion was 99.4°±23 for a gain of 26.7±20°. The final flexion and the gain in flexion were correlated with preoperative flexion (r=0.62 and r=-0.47, respectively). The final amplitude was 99±27° for a gain of 33±21°. The flexion gains were comparable for both types of malunion, whether they were intra- or extra-articular.

DISCUSSION

Arthroplasty provided a substantial gain in flexion. Osteotomy of the tibial tuberosity and the realignment osteotomies should be performed if necessary, with no risk of compromising the result. Superior gains can be sought in severe cases of limitation of flexion by releasing the extensor apparatus, in absence of cutaneous scar tissue retractions and recent infection.

LEVEL OF EVIDENCE

Level 4. Noncomparative retrospective study.

Soil respiration at mean annual temperature predicts annual total across vegetation types and biomes

Soil respiration (SR) constitutes the largest flux of CO(2) from terrestrial ecosystems to the atmosphere. However, there still exist considerable uncertainties as to its actual magnitude, as well as its spatial and interannual variability. Based on a reanalysis and synthesis of 80 site-years for 57 forests, plantations, savannas, shrublands and grasslands from boreal to tropical climates we present evidence that total annual SR is closely related to SR at mean annual soil temperature (SR(MAT)), irrespective of the type of ecosystem and biome. This is theoretically expected for non water-limited ecosystems within most of the globally occurring range of annual temperature variability and sensitivity (Q(10)). We further show that for seasonally dry sites where annual precipitation (P) is lower than potential evapotranspiration (PET), annual SR can be predicted from wet season SR(MAT) corrected for a factor related to P/PET. Our finding indicates that it can be sufficient to measure SR(MAT) for obtaining a well constrained estimate of its annual total. This should substantially increase our capacity for assessing the spatial distribution of soil CO(2) emissions across ecosystems, landscapes and regions, and thereby contribute to improving the spatial resolution of a major component of the global carbon cycle.

Breast Cancer Early Detection Awareness and Its Predictors in a Brazilian Nationwide Sample

Background: In contrast to developed countries, where breast cancer (BC) mortality has dropped in the past decade, BC associated deaths are still rising in Brazil. The absence of better structured screening programs and the lack of population awareness about the disease are among the factors for the high BC mortality in the country. Emphasizing the importance of mammography is a key factor in increasing the rate of early diagnosis and, therefore, the chances of cure. In this study, we aimed to quantify the population's recognition of mammography as an important exam, and evaluated factors associated with the awareness of its importance. Methods: A cross-sectional study was conducted with 1,344 women between 40 and 65 years old in 17 state capitals in Brazil. Women answered the following question: “In your opinion, what are the means that a person has to discover that she has breast cancer?” If a woman cited mammography in her answer, she was considered as aware in our analyses. Women also responded a questionnaire that included socio-economic status, educational level, healthy lifestyle behaviors, insurance plan coverage, and family history of BC, in order to identify possible predictors of greater awareness. The relationship between predictors and awareness was evaluated through univariate and multivariate modified Poisson regression. Results: Mean age was 51 ± 7 years; 53.5% of women were between 40 and 49 years old. 30% of the sample was from the higher and 18% from the lower social class. 12% had a positive BC family history, 75% used to visit their gynecologist at least once a year, 35% have a private health insurance, and 21% were current smokers (former smokers = 23%). Only 48.5% cited mammography as a tool to discover breast cancer. In the univariate analysis, younger age, higher level of physical activity, no current or past smoking habit, private health insurance, family history of BC, regular attendance to a gynecologist, and higher income, educational level and social class were all associated with higher awareness (p&lt;0.05 for all variables). In the multivariate model, which included all the former variables except for income and education (which had high collinearity with social class), the relative risks for greater awareness were the following: higher social class = 1.30 (1.05 – 1.61), BC family history = 1.11 (0.96 – 1.29), annual visit to gynecologist = 1.43 (1.18 – 1.75), no history of smoking = 1.17 (1.01 – 1.37), frequent physical activity = 1.10 (0.985 – 1.24), age &lt; 50 = 1.19 (1.06 – 1.33), private insurance = 1.20 (1.06 – 1.36). Conclusions: In this sample, with nationwide distribution, the awareness about the importance of mammography was low. Higher socio-economic status and healthy lifestyles were associated with a higher awareness of the exam's importance. The greater mammography awareness observed in younger women might reflect a higher general interest in its own health in this group, as well as its regular contact with reproductive health services.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3079.

Pretreatment serum TIMP-1 levels and survival in advanced pancreatic cancer

e15568

Background: Tissue inhibitor of metalloproteinase-1 (TIMP-1) has been shown to have diverse multifunctional roles in tumorigenesis such as inhibition of the catalytic activity of MMPs, growth promotion, inhibition of apoptosis and regulation of angiogenesis. Elevated TIMP-1 has been associated with an unfavorable prognosis in many cancers including breast, colorectal, gastric, head and neck, lung, and lymphoma. VEGF is also intimately associated with angiogenesis. Methods: This study determined serum TIMP-1 and VEGF levels in a phase III clinical trial of 157 patients with advanced pancreatic cancer. ELISAs for TIMP-1 and VEGF (Oncogene Science / Siemens HealthCare Diagnostics, Cambridge, MA) were employed to measure pretreatment serum TIMP-1 levels in 157 pancreatic cancer patients enrolled in a randomized, double-blind, placebo-controlled phase III trial. Statistical analysis was performed with TIMP-1 and VEGF on a continuous and cutpoint basis. Serum biomarker levels were then correlated with patient survival using Kaplan -Meier life table analysis. Results: Serum TIMP-1 levels in 157 pancreatic patients had a median of 409.9 ng/mL, and ranged from 144 to 1078 ng/mL. Patients with higher serum TIMP-1 had significantly shorter survival on a continuous basis (p = 0.001), on quartile analysis (p = 0.004), and on a dichotomous cutpoint analysis of upper 25 % vs lower 75 % (median survival 101 days vs. 197 days)(p< 0.001). Serum VEGF level was not associated with survival on a continuous (p = 0.57) or cutpoint analysis (p= 0.93). Conclusions: Pancreatic cancer patients with higher serum TIMP-1 levels had significantly shorter overall survival. Serum TIMP-1 level should be evaluated as a predictive factor for response to novel treatment regimens.

[Table: see text]

Differential contribution of extracellular and intracellular calcium sources to basal transmission and long-term potentiation in the sympathetic ganglion of the rat

Calcium involved in basal ganglionic transmission and long-term potentiation (LTP) can arise either by influx from the extracellular medium or release from intracellular stores. No attempts have yet been made to concurrently explore the contributions of extracellular and intracellular Ca2+ to basal ganglionic transmission or LTP. Here, we investigate this subject using the superior cervical ganglion of the rat. To explore the extracellular Ca2+ contribution, we evaluated basal transmission and LTP at different extracellular Ca2+ concentrations. To assess intracellular Ca2+ release, we explored the contribution of the calcium-induced calcium release process by overactivation or blockade of ryanodine-sensitive Ca2+ receptor channel with caffeine, and also by blocking either IP3R with Xestospongin C or the sarco(endo)plasmic reticulum Ca2+-ATPase pump with thapsigargin. Extracellular Ca2+ affected ganglionic basal transmission and LTP to different extents. While 25% of the physiological Ca2+ concentration supported 80% of basal transmission, 50% of normal Ca2+ was required to achieve 80% of LTP. Notably, disruption of intracellular Ca2+ release by all the drugs tested apparently did not affect basal ganglionic transmission but impaired LTP. We conclude that basal transmission requires only a small level of Ca2+ entry, while LTP expression not only requires more Ca2+ entry but is also dependent on Ca2+ release from intracellular stores.

Nasogastric Administration of Garenoxacin as Crushed Tablets With and Without Concomitant Enteral Feeding in Healthy Subjects

BACKGROUND AND OBJECTIVE

Cation-containing drugs have the potential to affect the absorption of quinolones. The current study was conducted to assess whether the bioavailability of garenoxacin was affected by administration as crushed tablets with and without concomitant enteral nutrition.

METHODS

This was a randomised, open-label, three-period, single-dose, crossover study carried out in healthy male volunteers who received study treatments at a clinical facility. The study included 18 subjects (mean age 30 +/- 6 years) who were treatment-naive to garenoxacin and had a body mass index of > or =18 kg/m(2) and < or =30 kg/m(2). Subjects received garenoxacin 600 mg orally in three treatments: (A) intact tablets; (B) crushed tablets suspended in water delivered via a nasogastric (NG) tube; and (C) treatment B plus concomitant enteral feeding (Osmolite; 600 mL at 100 mL/h). Serial plasma samples were collected post-dose for pharmacokinetic analysis. Pharmacokinetic parameters were determined by noncompartmental methods. Geometric mean ratio with 90% CI for area under the concentration-time curve from time 0 extrapolated to infinity (AUC(infinity)) and maximum observed plasma concentration (C(max)) were used to assess potential effects of the different conditions of administration. Absence of an effect was concluded if the 90% CIs for the ratio of geometric means for C(max) and AUC(infinity) were within 0.7-1.43 and 0.8-1.25, respectively. The pharmacokinetics (AUC(infinity)and C(max)) and safety of garenoxacin were assessed.

RESULTS

Geometric means for C(max) were 8.3, 8.5 and 8.3 microg/mL and for AUC(infinity) were 103.3, 97.2 and 93.4 microg.h/mL for treatments A, B and C, respectively. The 90% CIs for geometric mean ratios for AUC(infinity) and C(max) of garenoxacin administered as crushed tablets and crushed tablets with Osmolite via NG tube relative to intact tablets administered orally were within 0.80-1.25, suggesting that the bioavailability of garenoxacin was not affected by delivery of crushed tablets via NG tube, regardless of concomitant enteral feeding, compared with oral delivery of intact tablets. Half-life (mean range 12-13 hours) was similar for all three groups.

CONCLUSIONS

The relative bioavailability of garenoxacin was not affected by administration as crushed tablets, regardless of enteral feeding. Garenoxacin can be administered as crushed tablets in the presence or absence of concomitant Osmolite.

Effect of repeated oral administrations of the oral adsorbent AST-120 on serum creatinine and other markers of renal function. A randomized controlled study in patients with chronic kidney disease

BACKGROUND

AST-120 is an orally administered adsorbent used in Japan for prolonging time to initiation of hemodialysis and improving uremic symptoms in patients with chronic kidney disease (CKD). As AST-120 is suspected to reduce the progression of CKD by adsorbing renal toxins in the gastrointestinal tract, the objective of the current study was to determine whether binding of AST-120 to creatinine in the intestines could acutely alter creatinine balance, thereby limiting the utility of serum creatinine (sCr) as a measure of progression of renal function. Such information may be critical for the design of future studies to assess the efficacy of AST-120 in CKD patients.

METHODS

Patients with CKD (n = 20) received oral doses of AST-120(3 g t.i.d.) and placebo in a two-way crossover study. Blood and urine were collected for determination of sCr, 24-hour urinary creatinine (UcrV), creatinine clearance (Ccr), and urea nitrogen clearance (URCL). Differences between treatments were assessed using an ANCOVA model.

RESULTS

Following AST-120 and placebo treatments, mean sCr (1.73 and 1.79 mg/dl, respectively) and UcrV (1,264.73 and 1,286.05 mg) values were not significantly different. No significant differences were observed for Ccr and URCL.

CONCLUSION

These results indicate that AST-120 has no acute impact on creatinine balance in patients with CKD. Consequently, sCr and other markers of renal function are acceptable measures for assessing changes in renal function following AST-120 treatment.

Revisión de las interferencias entre los medicamentos más prescritos en el servicio de atención primaria de L’Hospitalet de Llobregat (ICS) y los análisis clínicos

OBJECTIVE

To analyse the concordance of published information on probable drug interactions and the results of clinical analyses.

DESIGN

Bibliographical review of the 50 most commonly prescribed drug products at the Primary Health Centre of L'Hospitalet de Llobregat, Barcelona, Spain, in 2002 and 2003.

DATA SOURCE

Six bibliographical sources consisting of drug product catalogues and reference books.

MEASUREMENTS

Interference with the 56 drug products studied.

RESULTS

Most theoretical interference belonged to the therapeutic group of anti-inflammatory drugs. The drug products with most interference were hydrochlorothiazide (diuretic) and gliclazide (lipid lowering). The most frequent interference was in the increase of transaminases, thrombocytopaenia, leukopaenia, hyperglycaemia, and hyperuricaemia. Only in 12% of the points of interference analysed was the rate of concordance among the various bibliographical sources reviewed higher than 50%. The highest rate of concordance was found in the diuretics.

CONCLUSIONS

Consultation of a single bibliographical source does not necessarily ensure the obtaining of reliable data on possible drug interference. This study demonstrates the need to standardize information on drug interference and to include the medication that the patient follows on the analysis application form.

Signal intensity of MR-images of thigh muscles following acute open- and closed chain kinetic knee extensor exercise – index of muscle use

Exercise-induced shifts in signal intensity (SI) of magnetic resonance (MR) images were examined to assess indirectly muscle use in closed- and open-chain knee extensor exercises. Eight men performed five sets of 8-12 repetitions in the leg press (LP) and the seated knee extension (KE) exercises at 50, 75 and 100%, respectively of the 5 x 10 repetition maximum (RM) load. Prior to exercise and after each load setting, images of the thigh were obtained. The increase in SI (Delta SI) of the quadriceps at 100% load was greater (P < 0.05) after KE (32.1 +/- 9.0%) than after LP (21.9 +/- 9.2%). Regardless of load, the four individual muscles of the quadriceps showed similar changes in SI after LP. The three vastii muscles showed comparable increases in SI after KE. M. rectus femoris showed greater (P < 0.05) Delta SI than the vastii muscles at 100%. Neither exercise produced increase in SI of mm. semimembranosus, semitendinosus, gracilis or biceps femoris. Mm. adductor magnus and longus showed increased (13.3 +/- 6.5%; P < 0.05) SI after LP, but not after KE, at 100% load. The present data also infer greater involvement of the quadriceps muscle in the open-chain knee extension than in the closed-chain leg press exercise. The results of the current investigation also indicate similar over-all use among the three vastii muscles in LP and KE, but differential m. rectus femoris use between the two exercises. This report extends the merits of the MR imaging technique as an aid to study individual muscle involvement in a particular exercise task.

Steady-state pharmacokinetics, pharmacodynamics and tolerability of donepezil hydrochloride in hepatically impaired patients

AIMS

To evaluate the pharmacokinetics (PK), pharmacodynamics (PD), tolerability and safety of donepezil HCl 5 mg following oral doses for 1 and 24 days in hepatically impaired patients compared with healthy controls under steady-state, multiple-dose conditions.

METHODS

In this single-centre, multiple-dose, open-label study, patients with impaired hepatic function (Child-Pugh grade A or B) and healthy controls (matched by gender, age and weight to the hepatically impaired patients) received a single 5 mg dose of donepezil on day 1 and then donepezil HCl 5 mg once daily from days 6 to 29. PK and PD (determination of erythrocyte acetylcholinesterase inhibition) parameters were evaluated on days 1 and 29. Treatment-emergent adverse events (AEs), vital signs, physical examination and clinical laboratory test parameters were monitored throughout the study.

RESULTS

A total of 35 subjects (18 patients with hepatic impairment and 17 healthy controls) were enrolled and 32 subjects (16 in each group) completed the study. On day 1 (following a single dose) hepatically impaired patients showed a significant decrease in T(max), while t((1/2)) and AUC(0-infinity) were significantly increased compared with the healthy controls. On day 29 (following multiple doses), AUC(0-24 h), C(max), t((1/2)), C(SS), and R(A) were significantly increased in hepatically impaired patients compared with healthy controls. AUC(0-24 h) increased by 47.6% in the patients with hepatic impairment compared with the healthy controls. There were no significant differences in PD between the groups, although at steady state, the mean AChE inhibition was 16.2% higher in the hepatically impaired patients. No serious AEs were reported and no subject withdrew from the study due to AEs. The most common AEs in both groups were headache and diarrhoea. No clinically significant changes from baseline were observed in vital signs, physical examination findings or electrocardiograms. There was a significant difference in the number of hepatically impaired subjects with abnormalities in serum glucose compared with healthy subjects. However, these elevations were not associated with AEs.

CONCLUSIONS

The results of this study suggest that patients with AD and mild to moderate hepatic impairment (Child-Pugh grade A or B) can be safely given donepezil 5 mg once daily and that this dose is associated with a nonsignificantly higher AChE inhibition than age-matched volunteers.

Pharmacokinetics and Safety of Ebastine in Patients with Impaired Hepatic Function Compared with Healthy Volunteers

OBJECTIVE

To assess the differences between patients with hepatic insufficiency and healthy subjects with regard to the pharmacokinetics, cardiac safety and overall safety of ebastine and its active metabolite carebastine.

DESIGN

Open-label parallel-group study.

PARTICIPANTS

24 patients with varying degrees of hepatic insufficiency, as categorised by the Child-Pugh classification, and 12 healthy volunteers.

METHODS

Healthy subjects and patients with Child-Pugh class A (n = 8) or B (n = 8) received ebastine 20 mg once daily for 7 days. Patients with Child-Pugh class C (n = 8) [single or repeated dose] received ebastine 10 mg. Plasma concentrations of ebastine and carebastine were determined for 23.5 hours following the initial dose on day 1 and for 96 hours following the dose on day 7 by using a sensitive liquid chromatography-tandem mass spectrometry assay with a minimum quantifiable limit of 0.05 microg/L for ebastine and 1.00 microg/L for carebastine. Hepatic function was assessed by blood clearance of indocyanine green 0.5 mg/kg administered intravenously on day 2. Cardiac and overall safety parameters were monitored.

RESULTS

Overall, the pharmacokinetics of ebastine were not modified by hepatic impairment. No correlation between ebastine pharmacokinetics and hepatic function, as expressed by indocyanine green clearance, was observed. Comparison of the effective half-life of ebastine and carebastine between groups did not show relevant differences. Therefore, no apparent accumulation of ebastine occurred, and steady-state concentrations of ebastine and carebastine were predictable from single-dose pharmacokinetics both in healthy subjects and in hepatically impaired patients. Finally, no apparent difference was noted in the safety of ebastine between patients with hepatic insufficiency and healthy subjects as assessed by evaluation of adverse events, vital signs and laboratory parameters.

CONCLUSION

Ebastine can be safely administered to patients with impaired hepatic function, as no clinically important differences can be anticipated from the pharmacokinetics and safety profile of ebastine/carebastine as compared with healthy subjects. Nevertheless, the dosage used in severely impaired patients (10mg daily) was half that used in patients with mild to moderate impairment, and any comedication did not include drugs affecting liver function; in clinical practice, both these factors should be taken into account.